Electrophysiological experiments with microelectrodes have been performed on mouse central nervous system neurons grown in tissue culture and on identified molluscan central neurons. Intracellular recording techniques, including voltage clamp analysis, have been used to study the physiology and pharmacology of these cells. Vertebrate peptides have been found which directly and significantly alter the basis of excitability of specific molluscan neurons, leading us to propose them as neurohormones. Research on tissue-cultured neurons has been directed at the mechanisms of action of clinically important anticonvulsants, anesthetics and convulsants. The tissue culture preparation has allowed us to examine the amino acid neuropharmacology of central neurons in much finer detail than had previously been possible. Almost all of the clinically relevant drugs appear to be modulating the pharmacology of the inhibitory amino acid GABA and the excitatory amino acid glutamate. Those that induce convulsions depress GABA pharmacology and those that reduce convulsions or anesthetize enhance GABA and/or depress glutamate pharmacology. The results suggest that tissue-cultured mouse central neurons are a useful model for high resolution study of CNS neurophysiology and neuropharmacology. BIBLIOGRAPHIC REFERENCES: Ransom, B.R. and Barker, J.L.: Pentobarbital selectively enhances GABA-mediated post-synaptic inhibition in tissue-cultured mouse spinal neurons. Brain Res. 114: 530-535, 1976. Barker, J.L., Neale, J.H. and Bonner, W.M.: Slab gel analysis of rapidly transported proteins in the isolated frog nervous system. Brain Res. 124: 191-196, 1977.